The present invention is related to a cooling tower and, more particularly to a kind of fluid dynamic cooling tower which injects liquid flow to form into a continuous screen of high velocity liquid flow to suck in cooling air from outside to make a heat exchanging process so as to achieve a cooling process.
In various industries, hot liquid flow may be produced during operation, and the heated liquid flow must be cooled down for another application. In the following discussion, the liquid flow indicates the water. However, the cooling tower of the present invention is also practical for use to cool down other liquid flow.
Currently, the most popularly used apparatus to cool down heated liquid flow is the cooling tower. Conventional cooling towers include two types, one is the forced draft type cooling towers and the other is the induced draft type cooling towers. In the forced draft type cooling towers, air fan is installed in the ground to force outside fresh air into cooling tower through conduit pipe so as to let the forced air be in contact with hot water to cool down the water. In the induced draft type cooling towers, induction fan is attached to cooling tower to induce air. Because induction fan is normally set at the top of the associated cooling tower, no conduit pipe is required in the induced draft type cooling towers.
In conventional forced draft type or induced draft type cooling towers, water flow which passes through cooling tower may be running along a reverse direction against air current or running to intersect air current. In either type of cooling towers, a heat exchanger which comprises beehive inner packing structure is installed inside a cooling tower to enlarge the contact area of water with air current.
Generally, a forced draft type cooling tower requires relatively a simple structure and less structural strength, because it needs not to support air fan or the related conduit pipe. However, because outside air is indirectly directed into cooling tower to exhaust through an air outlet far away from air inlet, the cooling effect is not as so good as expected.
In induced draft type cooling tower, outside air is uniformly induced into the lower portion of the tower through various air inlets made around the tower. Therefore, the cooling effect in induced draft type cooling towers is substantially better than forced draft type cooling towers. However, the structural strength of an induced draft type cooling tower must be reinforced so as to support induction fan. Because induction fan is set at the top of a tower to increase cross-sectional area, the structure of induced draft type cooling tower shall be made of steel or other reinforced material to resist against strong wind force. However, steel material is expensive and tends to get rusted to shorten the service life of a cooling tower. Further, steel structure is inconvenient to transport and difficult to build-up at job-site. Although some other plastic materials like FRP and etc., have been used to partly replace steel structure, the cost is still high.
Either in induced draft type or forced draft type cooling towers, air fan and motor are requisite for a cooling tower to work. In case a big scale of cooling tower is installed, supplementary accessories and mechanism such as driving shaft and reduction gear shall be equipped. In consequence, space consumption, installation cost and operational noise figure are inevitably increased. In conventional cooling towers, condensed water drips may be carried by air current to diffuse out of the towers because mist eliminator can not be installed in the air outlet.
U.S. Pat. No. 3,807,145 to Engalitcheff, Jr. et at. shows an injection cooling tower which is composed of a chamber having a mouth, a throat, a diffusion region and an exhaust opening. Water is injected into the throat and induces air flow into the mouth as well as mixed concurrent, generally horizontal flow in the diffusion region. Heat laden with saturated air is discharged from the exhaust opening and cooled water is collected adjacent to the exhaust end of the chamber. Because said injection cooling tower does not require the use of motor and air fan or induction fan to force or induce air draft to perform heat exchanging process, noise figure can be minimized during operation. However, the vaporous water flow can only induce a limited amount of air current which provides limited pressure.